THz Pulses Stimulate the Tail Segment Regeneration of the Earthworm Eisenia Andrei

Time course of the segment regeneration of earthworms is influenced by internal (neurotransmitters, hormones) and external factors (temperature, radiation). Applying standard experimental protocol and conditions it is possible to investigate the effect of distinct factors on segment regeneration ability of worms as final results. After anaesthesia 25 tail segments were removed from the body and operated animals were exposed to THz pulsed radiation (pulse energy 5 μJ, pulse duration 2 ps, mean frequency 0.5 THz, repetition rate 1000 Hz, exposure duration 5 min, spot size X mm), green light (515 nm wavelength, 5 μJ energies) twice on three consecutive days (treated groups, n: 10) or did not radiated (control group, n: 10). For segment counting and histological observation worms were sacrificed on the 14
^th
postoperative day.